package com.plusjun.cart.interceptor;

import com.plusjun.cart.to.UserInfoTO;
import com.plusjun.common.constant.AuthServerConstant;
import com.plusjun.common.constant.CartConstant;
import com.plusjun.common.vo.MemberRespVO;
import org.apache.commons.lang.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 在执行目标方法之前，判断用户的登录状态。并封装传递给controller目标请求
 * 需要使用一个WebMvcConfigurer实现类将拦截器配置到MVC中
 **/
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTO> threadLocal = new ThreadLocal<>();
    /**
     * 执行目标方法之前拦截
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        UserInfoTO userInfoTO = new UserInfoTO();
        HttpSession session = request.getSession();
        MemberRespVO member = (MemberRespVO) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (member != null) {
            // 用户登录了
            userInfoTO.setUserId(member.getId());
        }
        // 获取cookie中的数据
        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                String name = cookie.getName();
                if(CartConstant.TEMP_USER_COOKIE_NAME.equals(name)) {
                    userInfoTO.setUserKey(cookie.getValue());
                    userInfoTO.setTempUser(true);
                }
            }
        }
        // 如果没有临时用户，则分配一个临时用户
        if(StringUtils.isEmpty(userInfoTO.getUserKey())) {
            String uuid = UUID.randomUUID().toString();
            userInfoTO.setUserKey(uuid);
        }
        // 调用目标方法之前，将用户信息放入threadLocal中
        threadLocal.set(userInfoTO);
        return true;
    }

    /**
     * 业务执行之后，将临时用户放入cookie
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

        UserInfoTO userInfoTO = threadLocal.get();
        // 如果时临时用户，则设置cookie
        if(!userInfoTO.isTempUser()) {
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTO.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }

    }
}
